/*******************************************************************************
 * Copyright (c) 2012 joey.enfield.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/gpl.html
 * 
 * Contributors:
 *     joey.enfield - initial API and implementation
 ******************************************************************************/
package com.joey.software.fileToolkit;

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.File;

import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JFileChooser;

/**
 * http://java.sun.com/docs/books/tutorial/uiswing/components/filechooser.html
 */
/* ImagePreview.java by FileChooserDemo2.java. */
public class ImagePreview extends JComponent implements PropertyChangeListener
{
	ImageIcon thumbnail = null;

	File file = null;

	public ImagePreview(JFileChooser fc)
	{
		setPreferredSize(new Dimension(200, 100));
		fc.addPropertyChangeListener(this);
	}

	public void loadImage()
	{
		if (file == null)
		{
			thumbnail = null;
			return;
		}

		// Don't use createImageIcon (which is a wrapper for getResource)
		// because the image we're trying to load is probably not one
		// of this program's own resources.
		ImageIcon tmpIcon = new ImageIcon(file.getPath());
		if (tmpIcon != null)
		{
			if (tmpIcon.getIconWidth() > 150)
			{
				thumbnail = new ImageIcon(tmpIcon.getImage()
						.getScaledInstance(150, -1, Image.SCALE_DEFAULT));
			} else
			{ // no need to miniaturize
				thumbnail = tmpIcon;
			}
		}
	}

	@Override
	public void propertyChange(PropertyChangeEvent e)
	{
		boolean update = false;
		String prop = e.getPropertyName();

		// If the directory changed, don't show an image.
		if (JFileChooser.DIRECTORY_CHANGED_PROPERTY.equals(prop))
		{
			file = null;
			update = true;

			// If a file became selected, find out which one.
		} else if (JFileChooser.SELECTED_FILE_CHANGED_PROPERTY.equals(prop))
		{
			file = (File) e.getNewValue();
			update = true;
		}

		// Update the preview accordingly.
		if (update)
		{
			thumbnail = null;
			if (isShowing())
			{
				loadImage();
				repaint();
			}
		}
	}

	@Override
	protected void paintComponent(Graphics g)
	{
		if (thumbnail == null)
		{
			loadImage();
		}
		if (thumbnail != null)
		{
			int x = getWidth() / 2 - thumbnail.getIconWidth() / 2;
			int y = getHeight() / 2 - thumbnail.getIconHeight() / 2;

			if (y < 0)
			{
				y = 0;
			}

			if (x < 5)
			{
				x = 5;
			}
			thumbnail.paintIcon(this, g, x, y);
		}
	}
}
